On 24 November 2014 at 15:46, Calvin Morrison <mutantturkey_AT_gmail.com> wrote:
> On 24 November 2014 at 15:44, koneu <koneu93_AT_googlemail.com> wrote:
>> Greetings.
>>
>> Markus Wichmann wrote:
>>> compiling with -O3 will result in some broken binaries. Somewhere. Why?
>>
>> Because -O3 is very aggressive and should NOT be used. Especially not
>> when compiling/bootstrapping a system. In most cases it makes things
>> buggier and bigger, in some cases even slower. Use -O2.
>
> I've used -O3 for a long time in several projects that are heavily
> tuned and not noticed any issues. I think there is a large stigma
> around -O3 but if you just take a few minutes to read about -O3 you'll
> learn quickly what is safe to use and what could cause problems. You
> seem like a hater.

before you FUD, there's lots of good stuff, like vectorization, and my
two favorites

-finline-functions, which is great for having efficient code, while
making sure you code is readable.
-funswitch-loops, this is a great optimization which helps deal with
stupid programmers
Received on Mon Nov 24 2014 - 21:51:38 CET